Patent GB-423904-A (GB)
Title: Improvements in or relating to valves particularly adapted to control flow of fluid through large pipe lines
IPC: F16K31/04
Filed: 1934-06-05
Abstract: 423,904. Valves. FOELL, A. L., 2375, Tudor Drive, Cleveland Heights, Ohio, U.S.A. June 5, 1934, No. 16759. Convention date, April 3. [Class 135] A manually or electrically actuated valve particularly adapted for controlling the flow of blast furnace gas through pipe lines of large diameter comprises a pair of dished discs adapted to engage inclined seats mounted in a slight enlargement of the pipe line and arranged to be first withdrawn from the seats in a direction at right angles thereto and afterwards rotated into a position at right angles to the seats. The discs 27, 28 which may have wear resisting surfaces secured to their peripheries are secured to central bosses slidably mounted in sockets 14, 15 formed in a casing 12 welded to hollow trunnions 10, 11 passing through stuffing boses 34, 36 in the casing wall and supported in roller bearings 33, 35 carried by brackets 8, 9. The bosses are internally threaded to engage right and left handed threads on a shaft 22 mounted in the casing 12 and provided with a bevel wheel 16 engaging a bevel wheel 19 on a shaft 20 mounted in roller bearings in the trunnion 10 and extending to the outside of the casing. Corrugated diaphragms 29, 30 are secured to the discs and to flanges on the bosses, to prevent leakage and hold the discs against rotation. Stuffing boxes and sliding keys may be used in place of the diaphragms. A weighted arm secured to the outer end of the trunnion 11 is adapted to work between adjustable stops and pass through its neutral position when the valve is half open. The discs are operated in the desired sequence by a hand wheel or electric motor coupled through reduction gear to a toothed wheel 42 formed on a drum 40 secured to the shaft 20. The trunnion 10 has a radial arm 61 carrying a pivoted pawl itself provided with a pair of wheels one of which engages a helical groove 41 in the drum 40 while the other co-operates with an inclined projection 70 on the valve casing. When opening the valve the drum first rotates the shaft 20 to withdraw the discs from their seats. During this movement the larger roller moves along the helical groove, at last an inclined depression in the groove passes under the roller, so allowing the pawl to fall into a recess on the drum. However at this moment the other wheel engages the lug 70 and so prevents the lug falling fully into the recess, but further movement of the drum causes the pawl to engage the end surface of the recess thereafter the drum acts through the pawl and arm 61 to rotate the trunnions. During the initial closing movement the wheel moves off the lug 71 so allowing the pawl to fall deeper into the recess and so into engagement with the other end surface of the recess which is of reduced height and is continued by an inclined surface to the periphery of the drum. A vent valve opening into the main casing between the discs may be opened, when the main valve is closed, by a crank disc on the trunnion 11 acting through a link, pin and slot and lever. Alternatively a continuous flow of water may be passed between the discs, in which case the pin and slot mechanism is disconnected. Removable inspection covers may be fitted to the casing between the discs.